Evaluation of tumor marker test requests in a hospital setting

INTRODUCTION: Early diagnosis and treatment of oncological disease is extremely important and tumor marker tests are a valuable tool; however, requests for testing should not be used in excess or without sufficient cause. The aim of this study was to analyze and evaluate the appropriateness of requests for tumor marker tests at a single hospital.
METHODS: Tumor marker tests for carcinoembryonic antigen (CEA), cancer antigen (CA) 15-3, CA 19-9, and CA 125 performed by a single biochemistry laboratory between January 1, 2018 and December 31, 2019 were assessed retrospectively. These tumor markers can be used for screening, diagnostic confirmation, estimating prognosis, and monitoring for recurrence. The departments of internal medicine, gastroenterology, endocrine diseases, chest diseases, general surgery, gynecology and obstetrics, and medical oncology were the most common sources of the requests.
RESULTS: There were 1420 (40%) requests for CEA, 671 (19%) for CA15-3, 868 (25%) for CA 19-9, and 585 (16%) for CA 125 during the study period. A significant difference based on gender was determined in requests for CEA and CA 125 (p<0.001 and p=0.033, respectively). In all, 312 (22%) of requests for CEA markers, 202 (30.1%) for CA 15-3, 204 (23.5%) for CA 19-9, and 113 (19.3%) for CA 125 requests were above the reference range. Significant positive correlations were determined between age and CEA, CA 15-3, and CA 19-9 tumor markers (r=0.262, p<0.001; r=0.096, p=0.013; r=0.090, p=0.008, respectively). The preliminary diagnoses supporting the requests included non-specific pain, acute vaginitis, anemia, anxiety disorder, dyspepsia, neoplasia, and thyroid disorder.
DISCUSSION AND CONCLUSION: The results of this study suggest that outpatient clinics made an excessive number of tumor marker requests inconsistent with the preliminary diagnosis. Overutilization of laboratory testing incurs significant costs and affects workload, and may also have other potentially adverse effects on patient care.